Abstract Wastage of in-bed components in bubbling fluidized-bed combustors (FBC) has been a continuing problem. In response to this, there have been a number of attempts recently to develop testing techniques to help in the selection of resistant alloys and coating to resist wastage, and to determine the effect of critical process variables on the wastage. This paper summarizes what is known about the wastage in operating FBCs, to provide a basis for the qualification of the testing techniques.